Obsidian artifacts recently have been recovered from 18 archaeological sites on eight islands across the Kuril Island archipelago in the North Pacific Ocean, suggesting a wide-ranging distribution of obsidian throughout the island chain over the last 2,500 years. Although there are no geologic sources of obsidian in the Kurils that are known to have been used prehistorically, sources exist in Hokkaido, Japan, and Kamchatka, Russia, the southern and northern geographic regions respectively from which obsidian may have entered the Kuril Islands. This paper reports on the initial sourcing attempt of Kuril Islands obsidian through the analysis of 131 obsidian artifacts. Data from this research were generated through the application of portable XRF technology, and are used to address research questions concerning prehistoric mobility, exchange, and social networking in the Kuril Islands.